Very little of the code that was in /kern/<os> was actually architecture independent. Even things that at first glance appeared to be, actually patched architecture dependent parts of the kernel. Since there wasn't much shared code, I didn't feel any any large amount of effort should be put into sharing litterally 3 lines so unless we find a place where there is a lot of code, os dependent architecture independent code should go in it's proper directory in a namespace for that OS and simply be called by the source architecture and os dependend files.